The present invention pertains to a cleaning solution and a method of use thereof. More particularly, the present invention is directed to an aqueous solution for cleaning the ends of fiber optics and fiber optic connectors.
Isopropyl alcohol (isopropanol, IPA) is the customary solvent used to clean fiber optic connector end faces. It is commonly taught, in fact, to use industrial or spectroscopic grade methanol or isopropyl alcohol exclusively, because commercial grade isopropyl alcohol has traces of water and minerals. Knowledgeable fiber optic users traditionally teach away from using water-based cleaners; as a result, water-based cleaners are not widely used for fiber optic connector end face cleaning currently.
While it is commonly taught that water should not be used to clean fiber optic end faces, water does, nevertheless, find its way into the fiber end face during cleaning. Water is present as an impurity in the most common end face cleaning solvent, isopropanol.
Isopropanol (also known as isopropyl alcohol or IPA) is completely miscible in water and water is completely miscible in isopropanol. IPA is also hygroscopic, able to absorb moisture from the air. Isopropanol is commonly available and used at a variety of concentrations for fiber optic cleaning. Common concentrations of IPA/water solutions are 99.5 percent to 99.9 percent IPA with the balance being water, 91 percent IPA/9 percent water and 70 percent IPA/30 percent water.
The highest grade IPA is unable to remove both ionic and non-ionic contaminants such as buffer gels, lubricants, and oily residues in combination with dusty soils. In comparison, the cleaning strength and solubility of the IPA/water blends, including those listed above, have a limited ability to clean light soils and polar soils; but non-polar and heavy soils cannot be cleaned effectively with known IPA/water blends. Furthermore, existing IPA/water mixtures are flammable and must be transported as hazardous material, which incurs extra risk and expense.
Other known water-based cleaners contain non-volatile surfactants, non-volatile pH control agents, chelating agents and other additives such that any non-volatile component could be left behind after the liquid has evaporated and become a contaminant.
Water-based glass cleaners and general purpose cleaners which contain propylene glycol ethers are widely known and commercially available from many sources. However, those cleaners contain surfactants (e.g. linear alkyl benzene sulfates) to emulsify oily soils, bases (amines or hydroxides) to raise pH, and chelating agents (when formulations are made with hard or non-deionized water).
All other known fiber end face cleaning solvents are non-aqueous based solvents and have known deficiencies. For example, non-volatiles in other formulations can contaminate the end face. Metal containers require non-volatile chemicals because volatile chemicals corrode the metal. Water-based products used on metals require agents to prevent corrosion or require plastic containers. In addition, some solvents are flammable, and the non-flammable solvents tend to be very expensive.
Accordingly, there is a need for an aqueous fiber optic connector end face cleaning solution. Desirably, such a cleaning solution is formulated with volatile components that will not redeposit back onto the end face. More desireably, such a cleaning solution is non-flammable, economical, non-hazardous, and easy to use, transport, and handle.